Spring latch means



Dec. 13, 1966 w. R. SCHELLER SPRING LATCH MEANS Original Filed Oct. 25, 1963 INVENTOR.

WILFRED "R SCHELL-ER l w a q United States Patent Ofifice 3,292,137 Patented Dec. 13, 1966 3,292,137 SPRING LATCH MEANS Wilfred R. Scheller, New Cumberland, Pa., assignor to AMP Incorporated, Harrisburg, Pa. Continuation of application Ser. No. 319,020, Oct. 25, 1963. This application Apr. 21, 1966, Ser. No. 545,527 1 Claim. (Cl. 339217) This application is a continuation of application Serial No. 319,020, filed October 25, 1963, now abandoned.

This invention relates to a spring latch device, or means to latch an electrical connector element in a housing member.

It is known to provide an electrical connector element with a spring latch device in order to maintain the connector element latched within an opening or passageway of a mounting or housing means. The free end of the spring latch device generally is disposed in a recess of the opening or passageway, abuts against a shoulder thereof, or engages a latching surface of a mounting means. This is the case especially in conjunction with small electrical connector elements such as disclosed in US. Patents Nos. 2,682,038; 2,689,337; 2,741,750; 2,779,007, and 3,011,- 143, which are disposed in a mounting or housing means such as an insulating body, insulating block, vacuum tube socket and plugboard panel, respectively.

The spring latch device is generally formed during the stamping and formation of the connector element, and thereby extends outwardly from the plane of the material to which it is integrally anchored. After the connector element has been formed, it is then inserted within an opening or passageway in the mounting or housing means. This opening or passageway is just slightly larger than the part of the connector element to be disposed therein. As a result, the spring latch device is pushed inwardly toward the axis of the connector element during the insertion thereof within the opening or passageway until the connector element is fully inserted into position; then the spring latch device springs outwardly, thereby engaging the latching surface to latch the connector element in position.

It has been found that upon inserting the connector element within the opening or passageway to its latch position, the spring latch device is substantially flattened and stress is concentrated at the point of connection of the spring latch device to the body of the connector element, thereby causing the point of connection to become weakened so that the spring latch device does not assume its original position. This could result in the spring latch device failing to perform its intended latching function. Moreover, upon a force being applied to the connector element or connector means connected thereto in a direction opposite to the direction of insertion, the weakened lat-ch device could break away from the body. In addition to the stress applied to the spring latch device during insertion of the connector element within the passageway, an undesirable pre-stress is developed at the point of connection of the spring latch device during the forming thereof.

It is, therefore, a primary object of the present invention to provide a spring latch means on an electrical connector element which minimizes the stress applied thereto during insertion of the connector element within an opening or passageway of a housing or mounting means.

Another object of the present invention is to provide a spring latch means which retains its resilient characteristics after the connector element has been inserted into position so that the spring latch means performs its intended latching function without failure thereof.

A further object of the present invention is the pro vision of a spring latch means in a connector element which is easy to form during the forming process of the connector element, and which retains its resilient characteristics throughout the life expectancy of the connector element and of the equipment associated therewith.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in a conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it it to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIGURE 1 is a side elevational view of an electrical connector element incorporating the principles of the present invention therein;

FIGURE 2 is an enlarged, part-sectional view of the present invention;

FIGURE 2a is a view similar to FIGURE 2 but showing the theory of the invention;

FIGURE 3 is an enlarged, part-sectional view of a modification of the present invention; and

FIGURES 4-6 are side elevational and part-sectional views of a housing showing the connector element of FIG- URE 1 at the point of insertion, part-insertion and secured therein, respectively.

The present invention will be described in conjunction with a conventional connector element, and it is to be understood that the principles of the present invention can be utilized in conjunction with any other connector element to be secured within a housing or mounting means.

Turning now to the drawings, there is shown in FIGURE 1 a connector element C having a ferrule portion F in which a conductor means CM is secured by cold-forging or crimping techniques disclosed in US. Patent No. 2,600,012. Of course, conductor means CM can be secured to the connector element in any other well-known manner.

Connector element C also includes a body portion B which provides the electrical engagement with another connector element (not shown). Connector element C is preferably formed by shaping a sheet metal blank or strip of a suitable, electrically-conductive material such as brass, bronze or other alloy, the metal being sufliciently hard and resilient in order to provide excellent spring quality thereto, as well as being malleable to permit the cold-forging or crimping techniques mentioned above.

During the formation of connector element C, spring latch means S is formed in body portion B and includes part 1 which provides an area for anchoring the spring latch means to body portion B. Another part 2 extends away from part 1 and is freely movable relative to body portion B. Part 2 has a sharp bend at 3 which is spaced from anchoring part 1, and the part 2' of part 2 from bend 3 to the end thereof extends away from the longitudinal axis of connector element C at varying angles, depending upon the type of connector element, the recessed portion in which the spring latch means is to be disposed, and/or the opening or passageway in which the connector element is to be disposed. Thus, part 2 can be set at a position away from the longitudinal axis from 10-20, and as shown in FIGURE 2a, it is 16.

Free end 2" of part 2 is not as thick as part 2' in order to provide means to grip the area against which free end 2" engages.

Bend 3 is preferably spaced from anchoring part 1 a distance which is one-fourth the length of spring latch portion E of the connector element. vsertion force being applied to the connector element,

3 means S or L/4, however, it is obvious that this distance can be varied but it has been found that L/ 4 is the optimum distance.

Operation-With the disposition of spring latch means S, as shown and described hereinabove, when the connector element C is to be inserted within a passageway P of housing H which includes a section P having a iameter slightly greater than body portion B of the connector element, the connector element is inserted in passageway P until bend 3 engages surface H thereof (see FIGURE 4), which is an inclined portion between the outer part of the passageway and a section P which has a smaller diameter than the outer part of the passageway. The outer part of the passageway receive-s therein ferrule portion F of the connector element, inclined portion H receives part B of body portion B, and section P receives part B" of the body portion.

Forward of section P is a shoulder H" and forward thereof is another section P" having a smaller diameter than section P. Inclined part B" of body portion B engages shoulder H" to prevent the connector element from moving any further within the passageway, and electrical-engaging portion E of body portion B has a diameter slightly less than section P".

Thus, as stated above, after bend 3- has engaged surface H', force is exerted on the connector element to push same further within the passageway so that the spring latch means moves across section P, thereby causing spring latch means S to be moved toward engaging Upon further inspring latch means S engages shoulder H" and then moves across section P", thereby causing the spring latch means to become flattened, i.e,, part 2 between anchoring part 1 and bend 3 is bent slightly toward the longitudinal axis while part 2' is substantially disposed within the plane containing anchoring portion 1 (see FIGURES 2a and 5).

Further insertion force causes the connector element to be moved into its secured position, as shown in FIGURE 6, wherein the parts H, P, H and P of housing H engage corresponding respective parts B, B", B' and E of connector element C. The spring latch means S springs away from engaging portion E to its original position and engages inner wall W of opening 0 in the front part of housing H, in which engaging portion E of the connector element is disposed in order to be engaged by another connector element. Thus, as can be discerned, shoulder H" prevents the connector element from moving any further within the passageway, and spring latch means prevents the connector element from being removed by a force being applied to conductor means CM. Of course, the connector element can be removed from the housing by simultaneously moving spring latch means inwardly and exerting a removal force on the conductor means.

With the foregoing invention, when the spring latch means has been flattened during insertion of the connector element within the passageway of the housing, as shown in bnoken lines in FIGURE 2a, part 2 of the spring latch means moves slightly within body portion B and part 2' is slightly inclined from bend 3 to the outer surface of the body portion; therefore, part 1 is flattened and the spring latch means is flattened 170*164, or approximately 6. On the other hand, if no bend is provided at 3 in the spring latch means and the only area of flexion is at anchoring part 1, the spring latch means would be flattened 180-164, or 16-", which reresnlts in a great amount of stress being applied in one area, whereas in the present invention the amount of stress is applied in more than one area; namely, anchoring part 1 and bend 3, thereby distributing the amount of stress in a plurality of locations and not in one location. Thus, the amount of deflection of each part is less than the angle at which part 2 is disposed with respect to the longitudinal axis of the connector element.

The present invention, therefore, provides a spring latch means on an electrical connector element which minimizes the stress applied thereto during insertion of the connector element within an opening or passageway of a housing or mounting means, the spring latch means is easy to form in the connector element, and it retains its resilient characteristics throughout the life expectancy of the connector element.

FIGURE 3 illustrates a spring latch means S where there is clearance between the body portion B and the part of passageway P in housing H in which the connector element is to be finally disposed. As can be discerned, spring latch means S has a curved part 4 and another part 5 extending away therefrom at an angle from bend 6. During the insertion of the connector element into position, spring latch means S assumes the position as outlined in broken lines; and, upon the connector element reaching its final position, spring latch means S assumes its original position, as shown in non-broken lines, thereby latching the connector element in position in the same manner as pointed out above in connection with FIGURES 1 and 2.

It will, therefore, be appreciated that the aforementioned and other desira ble objects have been achieved; however, it should be emphasized that the particular embodiments of the invention, which are shown and described herein, are intended as merely illustrative and not as restrictive of the invention.

I claim:

An electrical connector assembly comprising in combination an electrical terminal and a dielectric housing memher; said electrical terminal having a stamped and formed body section and ferrule section, said body section defining a matable section matable with a complementary electrical terminal and including a lance member stamped out of said body section and extending outwardly therefrom in a direction away from a longitudinal axis of said terminal, said lance member having a first section and a second section, said first section having one end anchored to said body section and another end connected to one end of said second section to define a bend thereat, the other end of said second section being free, saidfirst section extending substantially parallel to said longitudinal axis and said second section extending outwardly from said first section at an angle of between 10 and 20 with said bend being located about one-fourth the length of said latch member, said ferrule section having U-snaped lugs secured on a conductive core and insulation of an insulated conductor; said housing member having a passageway therein provided with an abutment and'securin-g section; means on said terminal in engagement with said abutment to limit movement of said terminal in one direction; said free end of said lance member engaging said securing section to limit movement of said terminal in another direction, said lance member distributing bending stresses about said bend and said one end of said first section of said lance member, and said free end being beveled so as to eifectively grip said securing section.

References Cited-by the Examiner UNITED STATES PATENTS 2,318,651 5/ 1943 Penfold 339-205 2,477,895 8/1949 Pol-lock 339- X 2,779,929 1/1957 Sesny et al. 33918 X 3,027,537 3/1962 Hess et al 3392l7 X 3,031,640 4/1962 McKee 3392l7 3,058,091 10/1962 Henschen 339--2l7 3,076,171 1/1963 Hopkins 339-2l7 X 3,189,868 6/1965 Hatfield 339-217 X EDWARD C. ALLEN, Primary Examiner.

PATRICK A. CLIFFORD, Examiner. 

